1. Field
The present disclosure relates generally to communication systems, and more particularly, to a use of expressions with device to device (D2D) communications in a Long Term Evolution (LTE) based wireless wide area network (WWAN).
2. Background
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of a telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). LTE is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. LTE may support direct device-to-device (peer-to-peer) communication.
Currently, many devices may be operable in a cellular network. When a first device detects an expression (e.g., network-layer discovery identifier) of interest that is announced by another device, the first device may attempt to communicate directly with the device that announcing that expression. Currently, to establish a D2D communication link between the devices, serving mobility management entities (MMEs) negotiate a D2D context that may include at least a link security context (i.e. key and expiration), and possibly other link-layer parameters (e.g., quality of service (QoS), etc.). The D2D context is established to support communication at the application-layer (app-layer) for the pair of expressions. Since the devices may have multiple expressions to announce, it is possible that the same two devices might attempt to communicate due to discovery of a different expression, and each discovered expression normally requires a separate D2D context to be formed. Additionally, a device may have multiple expressions to announce at different times. This process can be assisted by the network. No functionality exists within the WWAN that allows the device and/or network to associate parameters with each announced expression, in order to provide different types of services/user experiences, control the type of expression authentication and link security protocols, allow expressions to be associated with UE identities, etc.
As the demand for D2D communication increases, there exists a need for methods/apparatuses for supporting D2D communications within LTE while minimizing use of WWAN resources.